Gas lift



Mach 1, 1949. J. 0. SANDERS GAS LIFT 2 Shets-Sheet 1 Filed Sept. 17, 1945 R mm m m; Q 0 q J/ p J w yfi B March i, 1949. J. o. SANDERS GAS LIFT Sheets-Sheet 2 Filed Sept. 1'7, 1945 Patented Mar. 1, 1949 UNITED STATES PATENT OFFICE GAS LIFT Joseph 0. Sanders, Vivian, La.

Application September 17, 1945, Serial No. 616,741

7 Claims.

My invention relates to well pumps, but more particularly to the gas lift type of pump that utilizes natural gas under pressure, compressed air -or other compressed gases as flowing mediums to bring oil to the surface of the ground.

I do not claim to be the first inventor of a gas lift type of pump for use in pumping oil out of oil wells. However, out of years of experience in the actual production of oil, I have devised my invention herein disclosed which brings to the gas lift type of pump decided improvements to overcome the principal defects in such lifts as known to the prior art. The prior art type of gas lifts with which I have been familiar have required the use of a wasteful quantity of natural gas in order to make them function at all. The prior art type of gas lifts with which I am familiar by failure of their designs are not adapted to strip a well of the last remaining foot or two level of oil in the oil sands.

The primary object of my invention is to provide a gas lift whereby natural gas under pressure may be introduced into an oil well beneath the normal liquid level of the well and when so introduced will lift the oil or mixture of oil and water in the well without causing a back pressure on the oil bearing sand.

Another object of my invention is to provide a gas lift construction that is adapted'to operate in a manner to strip a well of all the oil that can accumulate in it.

Another object of my invention is to provide a as lift construction arranged in a manner to expel compressed natural gas or other compressed gas in an upward direction surrounding the discharge opening of a standing check valve in a manner to make use of the upward flow of 'gas to create a suction force over the standing check valve to induce an upward flow of oil or oil and water into the stream of upward flowing compressed natural gas or other compressed gas.

Another object of my invention is to provide in a gas lift construction for use in oil wells choke tubes for regulating the flow of gas through the gas lift.

Other objects and advantages of my invention will be made apparent in my following detailed description of a gas lift embodying my invention illustrated in my accompanying drawings.

Referring to the drawings:

Figure 1 is a vertical section view showing the gas lift installed in a well.

Figure 2 is an enlarged vertical section view showing the upper portion of the gas lift illus trated in Figure 1.

Figure 3 is an enlarged vertical section view illustrating the lower portion of the gas lift illustrated in Figure 1.

Figure 4 is an enlarged vertical section view, in part section, illustrating a part of the gas lift illustrated in Figure 1.

Figure 5 is a cross sectional view taken on line 5-5 of Figure 4.

Figure 6 is an enlarged fragmentary view of a part of the construction illustrated in Figure 4.

Figure 'l is an enlarged fragmentary view of a part of the construction illustrated in Figure 4 and,

Figure 8 is'an enlarged fragmentary view of a part of the construction illustrated in Figure 3.

Referring to the drawings, numeral [0 designates a well casing into which is extended a string of tubing ll. Only a portion of the lower length of the'tubing H is illustrated. Only the lower perforated length of the casin I llshown positioned in the sand S is illustrated.

Natural gas under pressure or other com pressed gas G that is used to'operate my gas lift is conducted down. to my gas lift in the annular passageway defined by the casing Ill and the string of tubing H within the same. This annular passageway is blocked off by a packer I! on the section of tubing l3 forming a part of my gas lift and so positioned-as to compel the operating pressure fluid G to go through gas passages incorporated in my gas lift now to be described in detail.

The illustrated structure embodying my invention commences with the perforated connecting block l4 threadedly engaged with a string of tubing ll through the means of the threaded upper end I5 of the block H. A section of tubing l3 constituting a part of my gas lift is threadedly engaged with the lower threaded end l6 of the perforated block II. A centrally positioned fluid passage l1 extends entirely through the perforated block 14 and communicates with the string of tubing II and the lower tubing section 13 through the means of the lift tube l8 screwed into the lower internally threaded portion IQ of the fluid passage l1. A Venturi nipple 2|) is connected to the lower end of the lift tube l8 by means of a sleeve 2|.

The perforated connecting block I4 is also provided with gas passages 22 each commencing with a mouth portion 23 that communicates with the annular space between the perforated block II and the string of tubing ll through which annular space gas G under pressure is caused to flow through the gas passages 22, through the perforated connecting block ll into the annular space deflned by the section of tubing l3 and the lift tube l8 extended into it.

To prevent sand 8 fromentering the gas passages 22, a collar screen 2| through means of its peripheral flanges 2i and thescrews 23 is mounted circumferentially and spaced directly onto the perforated block ll in a position surrounding all of the mouth portions 23. As a further precaution in preventing sand S from entering the mouth portions 23, each mouth portion 23 is provided with a gas passage screen closure 21 which includes a threaded shell 28 welded directly to the perforated connecting block M in a. surrounding position to the mouth portion 23. A circular screen 23 held in place by means of a ring cap 30 threadedly engaged with a threaded shell 28 completes the gas passage closure 21.

A choke plug 3| which is threadedly engaged with the lower threaded end 32 of the gas passage 22 and threadedly connected to the check valve 33 by means of the sleeve 34 conducts the gas G under pressure through the gas check valve 33 in a definitely metered regulated manner dependent upon the size of the choke plug 3| chosen for the particular pumping job to be done. It is contemplated that with each gas lift made according to the teachings of my invention there will'be supplied to the user a number of sets of choke plugs 3| for him to select from. Some jobs will require a. greater flow of gas G than other jobs. The pressure of the gas G itself will also be one of the determining factors dictating the users selection of the proper size of choke plug 3| to use.

The gas check valves 33 are very necessary to prevent oil or muddy water from going back up through the choke plugs 3| to foul them during periods of time my gas lift is not operating.

The natural gas under pressure or other compressed gas G being used to lift oil to the surface of the ground after passing through the gas check valves 33 is conducted down to the bottom end of the section of tubing l3 in the annular space defined by the section of tubing l3 and the lift tube l3 positioned in the section of tubing l3.

The lower end of the section of tubing I3 is closed by means of an externally threaded block 35 connected to the section of tubing l3 by a collar 36. A short shield tube 31 of the same diameter as the section of tubing l3 threadedly engaged to the threaded block 35 depends from the threaded block 35.

During the operation of my gas lift, oil or other fluid F travels upwardly through the fluid tube 38 forming a part of the fluid check valve 39 and extending up through the block 35 threadedly engaged in the same sothat it may be nicely adjusted to bring the top of the valve cage 40 into the throat portion 4| of the Venturi nipple 20 for reasons to be explained later. The fluid check valve 39 is provided with a valve seat 42 and a ball valve 43 which is adapted to be lifted by an upward flow of oil or other fluid F as explained later. 7 i

From the lower end of the section of tubing l3 the direction of travel of the compressed natural gas or other compressed gas G is reversed. It

enters through the Venturi nipple 20 into the lift tube l8 to be conducted up through the lift tube l8, through the central fluid passage l1 and then into the string of tubing l| inwhich it travels up to the surface of the ground. The compressed natural gas or other compressed gas 4 G commences to do its work as it passes through the Venturi nipple 20 in the manner I shall now explain. r

The Venturi nipple 20 in functioning as a Venturi tube causes the flowing gas G to speed up in the throat portion ll of the Venturi nipple 23 with a great drop in pressure, a pressure which may be made to go below atmospheric pressure.

This reduced pressure creates a suction force at the mouth of the valve cage which is positioned in the reduced pressure area. Due to the suction force even in the case of a well that has such a slight depth of oil in it that the static oil head is toosmall to make the oil or other fluid F lift the ball valve 43 oil. of the valve seat 42, my improved gas lift will function.

The reader must keep in mind that the flow of gas G through the throat portion ll of the Venturi nipple 20 is regulated by the choke plugs 3| discussed earlier in this specification.

The compressed gas G after lifting the oil F or assisting in lifting it into the lift tube It becomes intimately mixed in a stream of oil and gas, G plus F, and carries it on up with it to the surface of the ground in the form of an oil foam or oil spray. It is due to the sucking action .of the pressure fluid G, gas or air, that my gas lift will operate to strip a well of its last few inches of accumulated oil in the'casing I0.

Having thus described my invention, I claim:

1. A gas lift for use with a string of oil producing tubing positioned within a casing comprising a section of tubing depending from andin communication with the string of oil producing'tubing, a closure means for closing the bottom of said section of tubing, a fluid tube extending through the closure means and above the same into the lower end of the section of tubing, an

elongated lift tube provided with an expanded a bottom end the inside diameter of which is made greater than the outside diameter of the upper end of the fluid tube, the lift tube being positioned inside of the section of tubing with its upper end placed in communication with the string of oil producing tubing and-.with its lower end spaced above the closure means and in a surrounding position with respect 'to the upper end of the fluid tube and a means for directing a flow of compressed gas upwardly through the lift tube into the string of oil producing tubing whereby a flow of gas up through the lift tube will create a sucking force at the upper end of the fluid tube to assist in drawing oil or other fluid through the fluid tube for mixing with the gas flowing up through the lift tube.

2. The device as claimed in claim 1 wherein the section of tubing is connected to the string of oil producingtubing by means of a perforated connecting block through which the lift tube communicates with the string of oil producing tubing and wherein the means for directing the flow of compressed gas upwardly through the lift tube includes gas passages extending from peripheral, vertical wall surfaces of the connecting block through the block to the annular space defined by the section of tubing and the lift tube positioned inside of the same and wherein there is provided a packing means between the section of tubing and the well casing whereby the annular space defined by the well casing, the section of tubing and the string of oil producing tubing above it may be utilized as a gas conduit for conducting compressed gas down to the gas passages.

3. A gas lift for use with a string of oil producing tubing positioned within a well casing comprising a section of tubing depending from a string of oil producing tubing, the section of tubing being closed at its bottom end by a closure means, a fluid passage extending through the closure means, an upward acting fluid check valve mounted at the upper end of the fluid passage inside of the section of tubing and adapted to permit only an inward flow of fluid through the fluid passage. an elongated lift tube positioned within the section of tubing, the upper end of which is positioned to communicate with the string of oil producing tubing, the lower end of the lift tube being positioned above the closure means in a surrounding position with respect to the fluid check valve and a means for introducing a regulated flow of gas through the bottom end of the lift tube whereby a flow of gas upwardly through the lift tube will assist in the opening of the fluid check valve to admit oil or other fluid into the upward moving stream of gas.

4. The device as claimed in claim 3 wherein the means for introducing a regulated flow of gas through the bottom end of the lift tube includes a plurality of gas passages in communication with the annular space defined by the section of tubing and the lift tube within the tubin and wherein a choke plug constitutes a portion of the length of each of the gas passages.

5. A gas lift for use with a string of oil producing tubing positioned within a well casing comprising a perforated connecting block attached to thelower end of the oil producing tubing, a depending elongated section of tubing'attached to the connecting block, a closure means for closing the lower end of the section of tubing, the closure means being provided with a fluid passage, an upward acting fluid check valve for closing the fluid passage positioned inside of the section oftubing adapted to permit only an inward flow of oil or other fluid into the section of tubing, an elongated lift tube positioned within the section of tubing the upper end of which communicates through the perforated connecting block with the string of oil producing tubing, the lower end of the lift tube being positioned above the closure means in a surrounding position with respect to the fluid check valve and a means for introducing a regulated flow of gas into the bottom end of the lift tube whereby an upward flow of gas through the lift tube will assist in the opening of the fluid check valve to admit oil or other fluid into the stream of upward flowing gas. 1

6. The device as claimed in claim 1 wherein the fluid tube is threadedly engaged with the closure means whereby the upper end of the same may be placed in adjusted vertical positions in the expanded bottom end of the lift tube and wherein the expanded bottom end of the lift tube constitutes a nipple fashioned in the shape of a Venturi tube.

'7. The device as claimed in claim 1 wherein the fluid tube is threadedly engaged with the closure means whereby the upper end of the same may be placed in adjusted vertical positions in the expanded bottom end of the lift tube and wherein the expanded bottom end of the lift tube constitutes a nipple fashioned in the shape of a Venturi tube and wherein there is provided a fluid check valve on the upper end of the fluid tube and-wherein there is provided a means for regulating the pressure of the gas directed upwardly through the lift tube.

JOSEBH O. SANDERS.

REFERENCES CITED The following references are of record in the file of this patent:

v UNITED STATES PATENTS Number 

